For three years, Catalonia has been at loggerheads with the central government in Madrid over whether the prosperous northeastern region - a fifth of Spain 's economy - could secede.
The latest round in that struggle, a Catalan parliamentary election held on Sunday in which separatist parties won almost 48 percent of the vote, fell short of the decisive victory secessionist forces had hoped for.
But neither did it do much to defang an issue that has become one of the most vexing for Spain 's conservative prime minister, Mariano Rajoy, threatening to destabilize Spain just as its economy has come out of a lengthy recession and banking crisis.
Instead, the outcome has left an exceptionally volatile issue to simmer on the front burner for Spain - and all of Europe - at a time when the European Union 's ability to find a unified response to crises has already been called into a question, whether on refugees, Greek debt or the euro.